v2.7 (2014/09/22) : updates to macros and API

Natha's Numenera v2.7 (2014/09/22)
No change to the character sheet.
Moved the API scripts and Macros files to Git.
Enhanced Readme.md.
Updates to the API functions and macros  :
1. New function/macro to apply damage to NPC (the Character must have
these attributes: "Health" and "Armor")
2. Update to the stats rolls (function and macros) : now they handle
damage effort and the chat output has been corrected.
Merge pull request #450 from NathaTerrien/master

v2.7 (2014/09/22) : updates to macros and API